Fluid dynamic properties of phyolitic magmas, Mineral Mountains, Utah. Part 1: Volatile content and flow characteristics. Part II: Physical properties

摘要

Part 1 describes rhyolites from southwestern Utah that display striking dissimilarities in morphology which are attributed to viscosity differences due to variations in water content. Temperature effects and fluorine concentrations are unable to account for the observed differences in morphology. Fluid dynamic calculations indicate that rhyolite flows of fluid aspect contained between 1 and 3% water upon eruption. More viscous domes contained less water which was expelled in pyroclastic eruptions preceding emplacement of the domal rhyolite magma.